Saunders and Saro Aircraft Since 1917

SAVE OFFLINE

Saunders and Sare Aircraft since 1917

Peter London

~

The outstanding Saunders-Roe SR.A/l jet flying-boat. (Saro)

• (

!

CONTENTS

ISBN 0 85177 814 3

Preface Acknowledgements History of the Companies Saunders T.l Saunders Kittiwake Saunders A4 Medina Saunders A3 Valkyrie Saunders A14 'Metal Hull' Saunders/Sara A 7 Severn Saunders/Saro A10 'Multi-gun' Saro/Segrave A22 Meteor Saunders-Roe A17 Cutty Sark Saunders-Roe A19 and A.29 Cloud Saunders-Roe A.21 Windhover Spartan Cruiser Saunders-Roe A27 London Saunders-Roe A33 Saunders-Roe S.36 Lerwick Saunders-Roe A37 Saunders-Roe SR.A/l Saunders-Roe SR.45 Princess Cierva W.14/Saunders-Roe P.501 Skeeter Saunders-Roe P.531, Scout and Wasp Saunders-Roe SR.53 and SR. 177 Appendix One: S.E. Saunders: First World War sub-contracted production Appendix Two: Second World War sub-contracted production of Walrus and Sea Otter Appendix Three: Second World War disposition of Saro plant Appendix Four: Helicogyres Appendix Five: Projects Appendix Six: Sara-Hiller 1033 XROE-l Rotorcycle Appendix Seven: Pre-Sara Simmonds/Spartan Aircraft Appendix Eight: B-class markings Index

© Peter M London 1988 Typeset by Witwell Ltd, Southport Printed in Great Britain for Putnam, an imprint of Conway Maritime Press Ltd, 24 Bride Lane, Fleet Street London EC4Y 8DR at the University Printing House, Oxford First published 1988

v

VII IX

1

52 54 60 64

71 76 85 92 96 109 125 130 144 162 171 191

196 210 236 263 276

298 298 299 300 303 327 328 340 341

Preface Saunders/Saro designed and built mostly flying-boats and amphibious aircraft, a natural evolution from an earlier involvement with boatbuilding. The aircraft varied greatly in terms of success. A number have gone largely unrecorded, especially some of the early prototypes. A small number of landplane designs were also conceived. The term 'Saunders/Saro' is used to describe a Limited Company which existed between 1908 and 1959. For twenty years, S.E. Saunders Ltd was engaged in boat-building, sub-contracted aircraft construction, and the development of a few aircraft to the company's own designs. In late 1928 the firm was reorganised and a new name was adopted-Saunders-Roe Ltd, usually abbreviated to Saro. The latter concern laid greater emphasis on aircraft design, and other interests were over a period made virtually autonomous. Despite fluctuations in the success of its aircraft, the company continued with its work and by the early 1950s was the last stronghold of flying-boat development in Great Britain. Saunders/Saro was always a small enterprise compared with the major aircraft manufacturers and so a frequently one-sided battle was waged in terms of obtaining orders and developing new types. It has been suggested that the company might have done well to concentrate solely on boat-building. Certainly a significant proportion of its aircraft remained unsold or were unpopular with those who flew them. Others, however, were more successful and a few were outstanding. This is the story of all these aircraft and the company which produced them.

VB

Acknowledgements The author wishes to acknowledge with gratitude the help of the organisations and individuals listed below. Without their co-operation, freely and generously given, this work would not have been completed. Army Air Corps; Aeroplane and Armament Experimental Establishment; Air Historical Branch (RAF); Aeronautical Quality Assurance Directorate (especially Ken Meekcoms); D.B. Allison; G. Allison; V.F. Arnold; L.S. Ash; Mrs D. Austin; Lord Balfour of Inchrye PC MC; British Aerospace; BBC Radio Solent; BBC Television South; British Hovercraft Corporation; British Powerboat Co; I.E. Bliss; G. Boothroyde; Chaz Bowyer; Civil Aviation Authority Library; Helen Cookson; Mrs W.E. Cozens; B. Dibbens; J. Hamon; H. Hanna; Mrs J Harpley; M Hermiston; Capt B. Hygate; Inspectorate of Recruiting RAF; Isle of Wight County Press; Imperial War Museum; Mrs M. Keen; Mrs D. Knowler; A.P. Kitcher; S.J. Lake; P.K. Langdon; D.E.C. Lockyer; A.G. London; Luftwaffen-Museum; Miss L. Manning; R.J. Mitchell Hall; I.R. Murray (HM Consul Porto); W.F. Murray; Mrs M. New; Parkhurst Photographic; Public Records Office; Liz Radcliffe; Bruce Robertson; S.J. Rose; Royal Aircraft Establishment Farnborough (especially Dennis Goode and Brian Kervell); Royal Aeronautical Society; Royal Air Force Association; Royal Air Force Museum; W.J. Saunders; Science Museum; L.G. Seager; Shell UK; c.A. Sims; Southern Evening Echo; B.J. Saxton; L. Smith; Mrs R. Stevenson; R. Stratton; John Stroud; Rev P. Tongeman; I.T. Ward; Westland Helicopters; Bob Wealthy; Mrs M. Woodhouse-Jones. Special thanks to Eric Morgan for his encouragement as well as practical support. This book is dedicated to my mother and father.

IX

l

History of the Companies Beginnings The origins of S.E. Saunders Ltd can be traced to the 1830s, when a small family business was established by Moses Saunders, an engineer by trade, in the village of Streatley, Berkshire. This enterprise was concerned with the construction of locks and weirs, as part of the process designed to make the Thames navigable as far as Oxford. Involvement with one kind of marine work encouraged Saunders to look at a more specific aspect; the science of boat-building. As the concern prospered it expanded, boatbuilding became its primary work, and the products, a series of high-speed steam launches, established a fine reputation. A variety of skiffs and punts were also constructed. Saunders even guaranteed their punt poles, offering to pay £20 to anyone who broke one under normal use-as far as is known, the firm never had to pay. Moses Saunders died in August 1859 but the business was continued by members of his family. As the demand for boats increased, premises were obtained at Goring, on the Oxford side of the Thames, in 1870. During the late 1880s, the firm opened a new and much larger site at the Spring field Works in South Stoke, and was gradually centralised there until 1901. In the late 1870s, meanwhile, while still situated at the Streatley and Goring sites, the concern was taken over by Moses Saunders' grandson, Sam. Sam Saunders was born in 1856, when the family still lived at Streatley. He grew up to be an untypical Late Victorian businessman; he lacked the complacency that ruined many of his peers. A single-minded and dynamic personality, Saunders was also shrewd, and looked enthusiastically for new ideas to improve his boats: As a boy, he had single-handedly constructed a small dinghy, which had received much acclaim from the villagers of Streatley. Marine work was in Sam's blood, and the company provided a solid basis on which to build. When reliable internal combustion engines became available, Saunders was one of the first to experiment with the idea of using such a powerplant in marine craft. His results were successful, and offered a good chance to capture a share in the then emerging market for high-speed motor-boats. Saunders did not stop at merely introducing new engines into old-fashioned hulls. He considered the possibility of improving hull strength to take full advantage of the increase in speed and power offered by the new engines, while at the same time remaining mindful of the necessity to minimise any weight penalty introduced by the strengthening process. Sam Saunders' method of hull construction was the result of logic and imagination combined. Laminated plywood skinning applied to hull structure had been attempted before Saunders' development but the bonding agents then available, casein and blood albumen, were prone to weaken after prolonged immersion in water. Neither was sufficiently fungus-proof. Saunders eventually found inspiration in the Canadian

l

Indian birch-bark canoes, the skins of which were stitched together with animal sinew. From this, he experimented with the idea of sewing laminated plywood constructed from Honduras mahogany (later mahogany with cedar), using as his 'thread' either annealed copper or occasionally brass wire. He soon found that here was an answer to the problem of a strong but light structure. Saunders' sewing method consisted of stitching the wire round the edges of the plywood sheets and at intervals across them, to prevent separation of the layers. This technique was later improved by sewing the wires in overlapping, staggered patterns, and, for added watertightness, by applying calico soaked in boiled linseed oil between the sheets. Hand-sewing the sheets was of course laborious and tiring, so Sam, aided by his daughter, converted a series of large (conventional) sewing machines to do the job more profitably. The sewn method of construction was given the name Consuta, and a 51 ft launch, completed in 1898, was named after it; a free advertisement. Consuta was still in use some 53 years later, by a BBC Television camera crew filming the Oxford and Cambridge Boat Race, and is currently under restoration by Graham Lindsay at Kew. The term 'Consuta' means in Latin 'stitched together', and interestingly it is also the name of a group of small plankton-like animals, which float rather than roam submerged. The Consuta principle was patented (No. 222) on 31 December, 1898. Convinced that here he had a technique with an important future, Sam formed the Saunders Patent Launch Building Syndicate in early 1899, his principal associates being Sidney Porter, a highly creative draughtsman, and Fred Goatley, a master boat-builder. Soon, boats with sewn hulls began leaving the Springfield Works regularly. Gradually, Springfield began to supersede Goring and Streatley in importance, the latter sites being let and used for storage of boats and spares. Consuta construction clearly had applications beyond small motorboats. When in the late 1890s Sam surveyed the boat-building industry as a whole, he saw that Cowes, on the Isle of Wight, was becoming the centre of British yachting, as well as for the very new sport of motor-boat racing, which was then gaining popularity. In 1901, he opened a branch works there, on the former site of a Wesleyan chapel at West Cowes. The Syndicate, their families and much of the labour force moved from Berkshire with him. Again, the firm expanded; new customers included Trinity House, the Admiralty, and the Eastern Telegraph Company. Soon after the new branch was established, Saunders was astute enough to acquire sole British rights to the Fauber Principle, which had been devised originally by the Rev C.M. Ramus and later resurrected by a Mr Fauber, an American resident in France. This involved a method of creating a stepped hydroplane hull, refined by Fauber through the concept of introducing air via tubes to a point beneath the hull just aft of the step. The effect created was to break the water suction behind the step, a measure designed to allow the hull to ride on the forward area only, thus reducing friction. Study of the idea gave Saunders an added insight into the development of fast waterborne craft. By the early 1900s Saunders was gaining an enviable reputation for competitive high-speed boats. A number of hulls for craft entering the British International Races at that time were built by the company, nearly

all of Consuta construction. New premises were opened near the Folly Inn at Whippingham on the Isle of Wight, for the manufacture of Cons uta on a large scale. Also, in 1906, Sam Saunders began to look into a new form of craft, his experiments being based at Springfield. Early that year the experimental craft was tested in model form. She was broad-beamed and flat-bottomed for most of her length. A full-size version appears to have been built at Springfield, but there is no surviving record of its performance. The craft was 33 ft long with a beam of 8 ft and a bottom which sloped up at the forward end. Two sidewalls were adopted as well as a centre wall, with fourteen fences between them, all running the full length of the hull. Through the hull bottom between the fences were cut a number of holes slanted aft, through which air was passed under pressure. The boat was propelled by the air thrust from the holes against the water and the air was contained between the sidewalls. The boat was thus planned to ride on an air cushion. This craft was designed by F.W. Schroeder; Saunders merely constructed it. What happened to the prototype is unknown, but it is fascinating to note that nearly 60 years later Sam Saunders' old site at Cowes would be used for the production of another type of vehicle riding on a cushion of air, the Hovercraft. 1906 was a formative year for Saunders. His agreement with the Launch Building Syndicate expired but he did not renew it. He felt that his inventive powers and freedom of action were being hampered by the commitment required for such a partnership. Though he did not sell the Springfield Works until January 1912, most of his assets were transferred to the Isle of Wight, where he acquired a bigger site. As it was derelict, he bought it cheap. After repairs had been made, the new yard, on the east bank of the Medina, was named Columbine. Finally, in 1908 Saunders converted his business into a private limited company. With capital of £5,000, aided financially by the Wolseley Tool and Motor Car Company, with himself as Chairman, the firm of S.E. Saunders Ltd was established. 1908 saw a continuing interest in the air cushion; Saunders filed a patent titled 'Hulls, Lubricating'. This patent suggested that air be injected to the hull underside of a boat, using sidewalls to prevent dispersal, to try to minimise the violent rising and falling of the forebody of powerful boats in rough waters. The intention was to achieve reduced drag and a smoother passage. On the practical side, as the interest in motor-boat racing grew, so did Saunders' success. Cowes-built craft soon made their presence felt in various racing competitions. Typical was the 49 ft Ursula built in 1909, which won the Coupe des Nations four years in succession. Another example was E. Mackay Edgar's Maple Leaf IV, a multi-step hydroplane, which was awarded the British International Trophy in 1912 and retained it the following year. Columbine, a 1910 hydroplane, took 14 first places and two second places from 18 starts at British motor-boat meetings. Another hydroplane, the 22 ft Rip III, achieved 31 mph using a 60 hp Vauxhall, while Angela, a similar type of 21 ft craft, made a planing maximum of 27 mph-this from a Wolseley engine of just 44 hp. Sam Saunders was determined to investigate as many outlets as possible to build up the firm. In November 1909, he announced his entry into the

2

3

i

L

The Ravaud craft on the Medina, early 1911. The new Saunders shed, in the background, was at that time under construction. (EHC)

then infant field of aeronautics. He placed a lot of confidence in the application of the Consuta principle in designs for 'aero navigation' because of its lightness and strength. Over the next 20 years or so, Consuta construction was used in a large number of aircraft designs. In January 1911, a particularly strange craft was launched onto the Medina from the Saunders sheds, then in the process of being expanded and rebuilt. Designed by a Frenchman, M. Roger Ravaud, this machine employed two transverse floats and an aerodynamic, rather than water, rudder for directional control. The craft was powered by a 50 hp Gnome aero-engine driving an airscrew rather than a water propeller. Indications are that it was fairly successful, though rather on the slow side; Ravaud intended installing a 100 hp Gnome, which he perhaps optimistically hoped would yield speeds of up to 60 mph. It is difficult to classify Ravaud's craft because it employed such a peculiar variety of features. Intended for Monaco, it never arrived; indications are that it operated in the Shoreham area instead. Participation in the construction of the Ravaud machine indicates Saunders' wish to explore new fields, perhaps the most attractive being in the aeronautical world. A number of aviation pioneers sought Saunders' aid because his method of Consuta construction followed their required criteria-lightweight but strong, an asset at a time of low-powered, unreliable aero-engines and dubious aerodynamic properties. Pertinent in shaping the future of the company was the interest shown by some of the pioneers in water-based aircraft. Once they had (after a fashion) mastered landplanes, they wanted to try something new, and Saunders' skill in producing resilient but light structures became sought after. During the years leading up to the First World War, the company supplied a number of floats and hulls for various experimental water-based aircraft, only some of which were succssful.

During early 1911 the concern built two engine gondolas for the rather unimaginatively-named Naval Airship Number 1 Mayfly, to house the 200 hp Wolseley motors, construction of the other components of the Mayfly being undertaken by Vickers. Mayfly was a rigid-type airship of 660,000 cu ft. Sadly, it broke its back, being hit by a gust as it was being taken from its shed, and never flew. In the autumn of 1912, Saunders was approached by T.O.M. Sopwith, who asked the company to build a hull for a small two-seat flying-boat he was designing. Saunders produced a beautifully streamlined 21 ft, 180 1b single-step hydroplane hull with side-by-side seating and a skin of Consuta, aided by Sydney Porter, who by that time was responsible for drafting most of Saunders' boats. External scoops were incorporated on the hull sides to inject air under the step. The hull itself was bolted to a conventional biplane superstructure carrying the tail assembly and the 90 hp Austro-Daim1er engine. Named Bat Boat, Sopwith's aircraft was exhibited at the February 1913 Olympia Aero Show and later purchased by the Admiralty for various tests, being consigned to the experimental station at Calshot. After research into bomb-dropping, at first using potatoes and later practice bombs, the Bat Boat was finally destroyed in a gale on 21 November, 1914, while at its war station at Scapa Flow, but was not officially struck off charge until the following March.

4

5

The Sopwith Bat Boat had a Saunders-designed hull and is seen here in its original, single fin and rudder, configuration. Initially, it was powered by an Austro-Daimler engine. (Hawker Siddeley)

In the summer of 1913, the Bat Boat took part in the Mortimer Singer Competition for British amphibian aircraft. Singer, the American sewingmachine magnate, had offered a prize of £500 for the first all-British amphibian to complete, within five hours, six out-and-back flights from land to a point on the water some five miles distant. The Bat Boat required certain alterations to become eligible for the competition. A retractable undercarriage was fitted, the Austro-Daimler engine replaced by a 100 hp Green, and the single rudder altered to twin configuration. The Bat Boat fullfilled the requirements of the competition on 8 July, 1913, the pilot being Harry Hawker and the official observer Lieut Spenser Grey RN, the Flight Commander at Calshot. Curiously, the competition sponsored by Singer had been won by an aircraft employing a sewn hull in its construction. The Bat Boat became the world's first successful amphibian and Sam Saunders could reflect that his company had played a significant part in its achievements. Saunders also became involved with other aircraft projects, though not always with such gratifying results. The third aircraft in the Bristol-Burney X series-the X.3-employed a Consuta-covered hull. This aircraft was an experimental type built to assess the possibility of a hydrofoil type undercarriage. Though initial towing tests made in August 1913 were fairly satisfactory, the sole X.3 was wrecked on a sandbank before a flight was made and the project was abandoned.

The sole Bristol-Burney X.3 experimental hydrofoil aircraft.

The Bat Boat in modified form, with twin fins and rudders, 100 hp Green, undercarriage and revised wing floats. (Hawker Sidde/ey)

Saunders also became involved, during 1912, with the ideas of Henri Coanda. A Rumanian, Coanda was a romantic whose aircraft were unorthodox at best. After causing mayhem at the British and Colonial Aeroplane Co, Coanda produced a bastardised GE 3 floatplane which was erected at Cowes. The first float absorbed too much water and was replaced by a Consuta example. The aircraft eventually stalled and sank on 15 April, 1912, while being flown by Harry Busteed. Autumn 1913 saw Saunders engaged in building another hull, this time for the Perry-Beadle biplane flying-boat designed by F.P. Hyde Beadle (who later designed the Saunders Kittiwake) and Copland Perry at Twickenham. The hull was again Consuta-covered, with the 60 hp ENV engine, enclosed in the bows, driving two airscrews via chain transmission. Streamlined to a fish-like profile reminiscent of some of Sir George Cayley's 'solids of least resistance', the hull was divided into two parts. The forward area was of deep section with a perpendicular bow, the underside forming a planing bottom. The rear portion was of monocoque construction with an integral fin and tailplane. A step was formed where these two structures joined. The lower wing and entire tail unit were also Consuta-covered; the upper wing was fabric-covered. In lieu of floats or sponsons, lateral stability was maintained by the watertight lower wing itself. The Perry-Beadle flying-boat was not a success. After its exhibition at the 1914 Olympia Aero Show, trials delayed by the start of war eventually took place in late July 1915 on Lake Windermere. Tests revealed that the aircraft floated with its lower wing trailing edge and lower rudder submerged, the drag preventing the aircraft from attaining flying speed. After the engine had been removed, the airframe was abandoned and subsequently broken up.

6

7

had won a large contract for the supply of lifeboats from the RNLI the first Admiralty order for a motor-boat and a Royal Warrant as Lau~ch­ Builder to His Majesty King Edward VII. The company had also been mvolved With a number of prototype aircraft from which some design and much constructIOnal expenence had been gained. A small contract for the production of several B.E.2 biplanes was also awarded to Saunders. With such considerable knowledge of boat-building, however, the company might reasonably have been expected to produce naval craft as its major contribution to the war effort. In fact the Admiralty decided that S~unders, because of its .experience with high-speed hull forms together With ItS knowledge of aIrcraft construction, should concentrate on the production of marine (and perhaps other) aircraft for the duration. Thus a fundamental change took place at Cowes during the early war years' transition from boat-building to aircraft production was completed befor~ the end of 1915, the sole maritime contract to survive being the continued output of lifeboats.

The First World War

Two other prototypes, of lesser importance, were completed at